Measuring method of throttling orifice flow rate in high pressure common rail injector

Abstract

The invention discloses a flow measuring method of a restriction orifice in a high-pressure common rail oil injector. The method comprises the following steps: firstly, the restriction orifice is arranged in the simulation test device and is tightly compressed and sealed with the simulation test device; the simulation test device is provided with a control valve, a control chamber and a control piston, which are identical to the actual operating state of the high-pressure common rail oil injector; the control valve is controlled through a travel distance measuring bar and a movement-control system to open and close; the travel distance measuring bar is controlled to move upward, high-pressure fuel oil is pumped in to pass through an oil inlet orifice into the control room; the control valve is moved upward under the action of the high-pressure fuel oil, so as to open an oil outlet orifice; the travel distance of the control valve is controlled by the travel distance measuring bar; fuel oil passes through the oil outlet orifice and finally discharged from an oil outlet; and the flow of the oil outlet is directly measured through a flow meter at the oil outlet, so as to obtain the flow of the restriction orifice. According to the invention, the flow measuring is carried out under a simulation working state, so that the actual flow of the restriction orifice in the high-pressure common rail oil injector can be effectively measured.

Description

technical field [0001] The invention relates to the technical field of performance testing of an electronically controlled high-pressure common rail injector, in particular to a method for measuring the comprehensive flow rate of a throttling orifice in an electronically controlled high-pressure common rail injector. Background technique [0002] The fuel injector is one of the important components in the fuel injection system of a diesel engine, which has an important impact on the performance and emission indicators of the diesel engine. With the improvement of national emission requirements and the application of high-pressure common rail technology, the injector of common rail system has become a research hotspot in the field of diesel engine fuel injection system technology. The structure of the high-pressure common rail injector is mainly composed of electromagnet, control valve assembly, oil inlet and outlet throttle orifice, control piston assembly, pressure regulati...

AI Technical Summary

Problems solved by technology

At present, the flow detection method of the throttle orifice in the production process is generally to inject 10MPa fuel oil into the oil inlet orifice of the throttle orifice, and install a flow meter at the oil outlet orifice of the throttle orifice. Therefore, the flow rate of the oil outlet orifice is directly tested. The defect of this detection method is that the detected flow rate of the orifice plate is not the actual flow rate of the throttle orifice plate in the working state of the common rail injector assembly, because the test method It did not take into account the actual assembly or actual working conditions, especially the damping effect of the gap formed between the control valve and the orifice plate mating surface on the fuel flow, and the pressure change of the control chamber when the orifice plate was working under high pressure. Factors such as the influence of the flow rate lead to a disconnection between the detection and the actual situation, resulting in the failure of parts that pass the flow test after being assembled on the injector body, and the performance of parts with the same flow rate installed on the same injector body is completely different. , which ultimately affects the control and improvement of the product quality of the fuel injector

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